About this Abstract |
Meeting |
2021 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2021)
|
Symposium
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Process Development
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Presentation Title |
Material Pressure Sensing at the Nozzle in Direct-write Additive Manufacturing Enables the Precise Fabrication of Complex Parts |
Author(s) |
Ali Asghari Adib, David John Hoelzle |
On-Site Speaker (Planned) |
Ali Asghari Adib |
Abstract Scope |
Flowrate control remains a challenge in extrusion-based Direct-Write (DW) Additive Manufacturing (AM) due to the capacitive energy storage in the system. Current open-loop control methods are material- and nozzle-dependent and any deviations in these parameters require an updated control design. Independent of the DW AM extrusion system, being pneumatic or mechanical, material pressure at the nozzle is statically related to output flowrate, enabling material-independent flowrate control. Here, we report on the design and implementation of a pressure sensing module that enables the in situ material pressure measurements at the nozzle in any DW AM system, and paves the way for precise control of material extrusion for fabrication of three-dimensional parts. The successful material- and nozzle-independent fabrication of parts using different nozzle sizes and materials that have different non-Newtonian rheological properties is demonstrated, and the shape fidelity of the printed parts is characterized to confirm enhanced printing accuracy. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |